docs: def hmac_sha1(self, key_handle, data, flags = None, final = True, to_buffer = False):
          """
          Have the YubiHSM generate a HMAC SHA1 of 'data' using a key handle.
  
          Use the L{pyhsm.hmac_cmd.YHSM_Cmd_HMAC_SHA1_Write.next} to add more input (until
          'final' has been set to True).
  
          Use the L{pyhsm.hmac_cmd.YHSM_Cmd_HMAC_SHA1_Write.get_hash} to get the hash result
          this far.
  
          @param key_handle: Key handle to use when generating HMAC SHA1
          @param data: what to calculate the HMAC SHA1 checksum of
          @keyword flags: bit-flags, overrides 'final' and 'to_buffer'
          @keyword final: True when there is no more data, False if there is more
          @keyword to_buffer: Should the final result be stored in the YubiHSM internal buffer or not
          @type key_handle: integer or string
          @type data: string
          @type flags: None or integer
  
          @returns: HMAC-SHA1 instance
          @rtype: L{YHSM_Cmd_HMAC_SHA1_Write}
  
          @see: L{pyhsm.hmac_cmd.YHSM_Cmd_HMAC_SHA1_Write}
          """
          return pyhsm.hmac_cmd.YHSM_Cmd_HMAC_SHA1_Write( \
              self.stick, key_handle, data, flags = flags, final = final, to_buffer = to_buffer).execute()